what is natural gas made of

Natural gas is a fossil fuel that is primarily composed of methane, a compound with one carbon atom and four hydrogen atoms (CH4) . It also contains smaller amounts of natural gas liquids (NGLs) and nonhydrocarbon gases, such as carbon dioxide and water vapor. While methane is the primary component of natural gas, it can also include ethane, propane, butane, and pentane. Natural gas is formed when layers of organic matter decompose under anaerobic conditions and are subjected to intense heat and pressure underground over millions of years. The energy that the decayed organisms originally obtained from the sun via photosynthesis is stored as chemical energy within the molecules of methane and other hydrocarbons.